Retractable antislip device for footwear

Abstract

 A retractable antislip device embedded in a footwear sole comprising a toothed bar (3) housed in a corresponding groove (2) formed in the sole and movable through the groove from a first position in which it is completely retracted in the sole to a second position in which it protrudes therefrom, and actuating means (4, 8, 11) for moving the toothed bar from the first to the second position and vice versa manually operable by an user. The actuating means comprise a sliding member (4) integral to the toothed bar (3) movable within the sole in a direction substantially perpendicular to the lying plane of the sole and a shaft (8) pivotally housed in the sole perpendicularly to the sliding member. The shaft has an outer end formed with means (11) for rotating the shaft around its axis and is connected to the sliding member in such a way that a rotation of the shaft in either direction corresponds to a movement of the sliding member and the toothed bar integral therewith from the first to the second position and vice versa.

Description

[0001] The present invention relates generally to the field of footwear and in particular relates to a retractable antislip device for footwear.

[0002] In the hierarchical scale of needs, after satisfying his primary needs, such as, above all, physiological needs (food, water, sex), man feels the need for security, that is to say, the necessity to be protected from illness, injury and, more generally, from unexpected events which restrict his own physical integrity.

[0003] The dangers which threaten man's personal safety are often connected to slippery, uneven unexpected terrain, to be found at any latitude: in the mountains, on the plain, in town or in the country.

[0004] Such dangers affect the entire civil population of the world, without distinction of age, sex and behavioral habits.

[0005] With reference to the World Health Organization's - Report of 2001, on which we based our research, the causes of disability through falls in people aged from 15 to 44 years inclusive are in third place after Hiv/Aids and ischeamic cardiac disease.

[0006] The prevention of traumatic episodes resulting in falls because of lack of grip on terrain which has become slippery through rain, constant wetness, grass, unevenness, sloping ground and for other reasons, represents a long-felt need. As well known, the traumatic effects from falls may have particularly serious consequences for older people, social unproductivity (the cost of medical treatment and rehabilitation therapy), and the like, whose costs fall to the collectivity.

[0007] While we have come across a variety of devices designed to be mainly mounted on heavy boots for use in icy and snowy conditions, up till now we have not yet come across any universal accident-prevention system for footwear which can be used reliably in all dangerous situations including asphalt pavements as well as risky terrain in the countryside and can be built into any type of footwear.

[0008] For instance, US 3717238 discloses a retractable antislip device for skiboots and similar articles of footwear comprising a casing embedded in the sole or heel of the shoe and a longitudinal rotatable camming member mounted therein over a longitudinal plate provided with depending spurs accessible through openings in the bottom wall of the casing and extensible downwardly from the bottom plane of the sole or heel. The plate member is biased upwardly by springs to retract the spurs. The rotatable camming member has a radial handle element at its end which is accessible by the user for manually operating the cam. However, this device is so structured as to be unfeasible its embedding within a sole or heel of limited thickness such as the every day shoes.

[0009] The invention consists in an universal retractable device, with an anti-slip function, placed in the thickness of the sole and more specifically in the heel's portion and/or the front portion of the sole. The device comprises a toothed bar housed in a corresponding groove formed in the sole and movable through the groove from a first position in which it is completely retracted in the sole to a second position in which it protrudes therefrom, and actuating means for moving the toothed bar from the first to the second position and vice versa, manually operable by an user. The actuating means comprise a sliding member integral to the toothed bar movable within the sole in a direction substantially perpendicular to the lying plane of the sole and a shaft pivotally housed in the sole perpendicularly to the sliding member. The shaft has an outer end formed with means for rotating the shaft around its axis and is connected to the sliding member in such a way that a rotation of the shaft in either direction corresponds to a movement of the sliding member and the toothed bar integral therewith from the first to the second position and vice versa.

[0010] The device is preferably placed in the heel and in the front portion of the sole of the footwear through seats shaped on purpose to receive it with the sides perfectly sticking to the mechanism. The device is simple and structured to be put in all thicknesses of the sole with all kinds of materials both with a smooth profile and/or wrinkled on the sole's surface in contact with the ground.

[0011] The device is embedded in the sole at the sole manufacturing step, on the inner part, irremovably integral with it.

[0012] The device used gives the footwear the possibility to be used in two ways:

a - with anti-slip function

b - normally, as usual.

[0013] The anti-slip function is started by protruding a toothed bar from the heel and/or from the front portion of the sole which, forced by a movement perpendicular to the sole/heel surface and preferably guided by its sides, allows the teeth distributed on the whole surface of the bar, to get a grip on the ground.

[0014] The normal usage of the footwear is possible thanks to the retractability of the device, which causes up to the complete disappearance the previously protruded teeth to be retracted in the inner part of the sole.

[0015] The device is particularly light (reduced number of parts); its dimensions do not modify the shape and design of the footwear and do not make the shoe heavy with the use of thicker soles.

[0016] The advantage is particularly appreciated in the work shoes, whose use lasts all day, as occurs for example in industrial refrigeration plants.

[0017] Further features and advantages of the device according to the invention will be apparent from the following description of an exemplifying, non-limiting embodiment thereof made with reference to the attached drawings, in which:

• figure 1 shows a bottom plan view of a heel portion embedding the device of the invention;
• figure 2 is a sectional side view of the device taken along line II-II of figure 1 and shown in the protruding position;
• figure 3 is a sectional side view of the device of figure 1 in the retracted position;
• figure 4 is a partial side view of the device of figure 1, according to arrow F of figure 1;
• figure 5 is a first variation of the device of figure 1;
• figures 6 and 7 are sectional side views of the device of figure 5 taken along line VI-VI and shown in the protruding and retracted position respectively;
• figure 8 is a second variation of the device of figure 1;
• figures 9 and 10 are sectional side views of the device of figure 8 taken along line IX-IX and shown in the protruding and retracted position, respectively.

[0018] With reference to the figures 1 to 3, 1 schematically denotes a sole portion, namely the heel portion, of a shoe in a bottom plan view. An arc-shaped groove 2 extending substantially perpendicularly to the longitudinal axis of the shoe indicated at Y-Y in figure 1 is formed on the bottom surface of the heel 1. A correspondingly shaped bar 3 is placed in groove 2 and is slidable in a substantially perpendicular direction to the lying plane of the sole or to the heel surface. Bar 3 is integrally connected to a piston 4 slidingly engaged in a seat 5 formed at an intermediate point of groove 2 in the heel portion and perpendicular thereto. A perimetrical slot 6 is formed on the lateral surface of piston 4 and a pin 7 is engaged in slot 6 and is slidable circumferentially along it. Pin 7 extends eccentrically from an inner end of a shaft 8 pivotally housed in a seat 9 extending perpendicularly to piston 4 and radially from an edge 1a of heel 1. In this way the outer end of shaft 8 is accessible to the user to angularly displace shaft 8 around its longitudinal axis.

[0019] In order to avoid shaft 8 from escaping from seat 9, a portion 8a of reduced diameter is formed at an intermediate point thereof and a pin 10 is forcibly engaged therewith perpendicularly to the surface of the heel. As shown in figure 4, the outer end of shaft 8 is provided with a manually operable diametrical rib 11 through which the shaft can be rotated angularly in either direction by 180°. The rotation of shaft 8 causes pin 7 to move according to a circular trajectory coaxial to the longitudinal axis of shaft 8 and, consequently, piston 4 to move in the seat 6 in the axial direction thereof.

[0020] A plurality of toothed projections 12 extend from the face of the bar 3 opposite to piston 4. In particular, toothed projections 12 consist of nine teeth. The movement of piston 4 in a first axial direction causes the toothed projections 12 to protrude from the bottom surface of the heel to provide a grasping action on a slippery ground, while the movement of piston 4 in a second, opposite axial direction causes the toothed projections 12 to retract within groove 2 to avoid any unnecessary hindrance to the user movements. The end-stroke positions of pin 7 lie on an axial plane with respect to piston 4, whereby an axial force acting perpendicularly on pin 7 when the toothed projections 12 are in their protruded position does not cause a rotation of shaft 8 that would result in an unwanted retraction of the toothed projections.

[0021] An O-ring 13 is placed in a circumferential groove 14 formed on the shaft 8 to ensure a proper sealing.

[0022] The arc-shaped form of toothed bar 3 has proven to be the most effective for the heel portion of a shoe sole because the user weight is better distributed evenly on the heel's surface and help walking with less effort. Thanks to the arc-shaped form, back swing problems occurring when grasp points are placed on a straight line perpendicular to the sole longitudinal axis are prevented.

[0023] As an alternative to the diametrical rib 11 at the outer end of shaft 8 a diametrical notch can be (not shown) formed to rotate the shaft by engaging a metallic coin therein.

[0024] While for the heel portion of a sole an arc-shaped toothed bar 3 is preferred, for the front portion of the sole a linear toothed bar 3' can be used. Toothed bar 3' is slidably arranged in a linear groove 2' as shown in figures 5 to 8. More than one toothed bar 3' and 3" , placed in corresponding linear grooves 2' and 2", can be also provided as shown in figures 9 to 11. The single or double toothed bar 3' and 3" are moved in a direction perpendicular to the sole surface by piston 4, to which they are integral, and piston 4 is moved axially by rotation of shaft 4 exactly in the same way as described above for the arc-shaped toothed bar.

[0025] Clearly a shoe sole is preferably provided with both types of retractable toothed bar, i.e. the arc-shaped toothed bar in the heel portion and at least one linear toothed bar in the front portion of the sole.

[0026] The means for moving piston 4 axially, i.e. shaft 8 with eccentric pin 7 and actuating rib or notch 11, can be arranged in any radial position with respect to piston 4 as shown in dotted lines in figures 1, 5 and 8 according to functional and design needs.

[0027] Variations and/or modification may be brought to the antislip device for footwear according to the present invention without departing from the scope of the invention as set forth in the following claims.

Claims

1. Retractable antislip device embedded in a footwear sole comprising a toothed bar (3) housed in a corresponding groove (2) formed in said sole and movable through said groove from a first position in which it is completely retracted in said sole to a second position in which it protrudes therefrom, and actuating means (4, 8, 11) for moving said toothed bar (3) from said first to said second position and vice versa manually operable by an user, characterized in that said actuating means comprise a sliding member (4) integral to said toothed bar movable within said sole in a direction substantially perpendicular to the lying plane of said sole and a shaft (8) pivotally housed in said sole perpendicularly to said sliding member (4), said shaft having an outer end formed with means (11) for rotating the shaft around its axis and being connected to said sliding member in such a way that a rotation of said shaft in either direction corresponds to a movement of the sliding member and the toothed bar integral therewith from said first to said second position and vice versa.

2. Retractable antislip device according to claim 1, wherein an arc-shaped toothed bar (3) is provided in the heel portion of the sole and at least a linear toothed bar (3', 3") is provided at the front portion of the sole.

3. Retractable antislip device according to claim 1 and 2, wherein said sliding member (4) is slidingly housed in a corresponding seat (5) formed in the sole and has a perimetrical slot (6), said shaft (8) having an inner end with a pin (7) eccentrically extending therefrom and slidably engaging with said perimetrical slot (6).

4. Retractable antislip device according to any one of the previous claims, wherein said shaft (8) extends radially within said sole from said sliding member (4) to an outer edge (1a) of the sole, at which the outer end of said shaft is accessible by the user for operating its axial rotation.

5. Retractable antislip device according to any of the previous claims, wherein said means for rotating said shaft comprise a diametrical rib or a diametrical notch (11) formed at the outer end of said shaft (8).

Drawing